Unfortunately the environment looks broken. (You can tell that by the green colour on the shell prompt)
When leaving the tutorial and returning you should not be running the Rebuild and Reopen option. It will delete all your progress. Instead on your return you should be clicking on the “reopen in docker” link.
The only path forward may be to reset (click reset) and then open a new bash terminal (do not use the one with the green prompt). If the new terminal opens and the prompt is blue then you will be able to continue.
If that doesn’t work, you will need to copy the rdb-alpha to a new path with a different name and then run code . from there to get a chance to restart this course from scratch in a rebuilt environment. (So in the new path you would run rebuild and reopen one time, at the start and then never again)